Erbis

Erbis is a fictional planet featured in the science fiction novel "The Crimson Star" by author J.X. Reynolds. It is depicted as a terrestrial world located in the Kepler-186 system, notable for its unusual atmospheric composition. Erbis has a predominantly nitrogen and argon atmosphere, with trace amounts of methane and ammonia, which gives its sky a perpetual twilight hue. The surface of Erbis is characterized by vast, windswept plains dotted with shallow, saline lakes and towering crystalline rock formations.

The planet's flora is sparse and adapted to the low light conditions and mineral-rich soil. It consists primarily of bioluminescent fungi and hardy, silicon-based vegetation that draws nutrients from the planet's subsurface geothermal activity. Animal life on Erbis is scarce and largely subterranean, with only a few species of exoskeletal arthropods venturing to the surface during the planet's brief periods of dim sunlight. The native inhabitants of Erbis, known as the Xylos, are a sentient, silicon-based lifeform that has developed a complex society based on subterranean cities and a deep understanding of the planet's geological processes. They are described as having a crystalline appearance and communicating through a series of resonant frequencies. The story of "The Crimson Star" explores the interaction between human explorers and the Xylos, and the discovery of valuable mineral resources on Erbis.